DEVELOPMENT AND IMPLEMENTATION OF ENDOCRINE BIOMARKERS OF EXPOSURE AND EFFECTS IN AMERICAN ALLIGATORS (ALLIGATOR-MISSISSIPPIENSIS)

This study reports on the developmental effects of potential xenobioti c substances that may alter endocrine physiology during embryogenesis in the American alligator (Alligator mississippiensis). Eggs collected from a wild population were treated with either 2,3,7,8-tetrachlorodi benzo-p-diosin (TCDD), o,p'-DDE, p,p'-DDE, ethynylestradiol, coumestro l, or indole-3-carbinol at several dose levels. Treated eggs were incu bated at temperatures that normally produce all male hatchlings (33 de grees C). Several biochemical and morphological endpoints were evaluat ed from hatchling alligators at three weeks of age. Sex determination contrary to that expected by incubation temperature was exhibited by t hose embyos treated with ethynylestradiol, p,p'-DDE (higher doses), an d TCDD (higher doses). Control alligator embryos resulted in predomina tely male phenotypes. Vitellogenin induction was not apparent in xenob iotic-treated alligator hatchlings, and this may be a reflection of th e fact that these animals possessed substantial abdominal yolk reserve s. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.